TM55-2840-251-23Section XENGINE TESTING (Continued)1-94GROUND TEST OF ENGINEINSTALLED IN AIRCRAFT(Cont)9.c.(Cont)(4)With propeller in fine pitch and oiltemperature at 100'F (38'C)minimum, observe and recordNg at idle speed.(5)Disconnect Py sense tube between FCUand power turbine governor at the FCU, and check if Ngdrops from the value recorded in subparagraph c.(4).Reconnect Py sense tube.NOTEDuring this check the engine will not respond topower control lever movement. Leave thecontrols in the Lo-idle position.CAUTIONCarry out this check with zero powerextraction. Should the minimum fuel flowstop be adjusted too low, an excessive dropin Ng will result and the operator must beprepared to shut down the engine ifnecessary.(6) If Ng, with Py sense tube disconnected,was less than Ng recorded in subparagraph c.(4), thenengine was governing at the idle speed setting and the idlespeed may be adjusted in accordance with subparagraphb.(5).GO TO NEXT PAGE1-159